ACTIVE NOISE AND VIBRATION CONTROL FOR AUXILIARY POWER UNITS

THIS PROJECT ADDRESSES SYSTEMS TO REDUCE NOISE AND VIBRATIONS EMANATING FROM AUXILIAIY POWER UNITS (APUS) WHICH ARE BEING INITEGRATED INTO ARMY VEHICLES AND SHELTERS. EXCESSIVE NOISE AND VIBRATIONS ARE HARMFUL TO AND HINDER THE EFFECTIVENESS OF OPERATORS AND OCCUPANTS. IN MILITARY EQUIPMENT, IT IS ALSO BENEFICIAL TO AVOID EMANATIONS THAT MIGHT BE USED AS DETECTION SIGNATURES . THIS EXPLORATORY DEVELOPMENT WORK WILL INVESTIGATE THE FEASIBILITY OF DESIGNING AN ACTIVE NOISE AND VIBRATION CONTROL (ANVC) MODIFICATION KIT FOR APUS. THE PHASE I ACTIVITY WILL PRODUCE DESIGNS FOR TWO REPRESENTATIVE APU MODELS, THE 10 KW AND 30 KW UNITS. A PRIMARY REQUIREMENT IS THAT INTERNAL AND EXTERNAL NOISE BE REDUCED BY IO DB(A). AFFORDABLE ANVC SYSTEMS ARE ATTAINABLE BY APPROPRIATE INTEGRATION OF CONTRIBUTIONS FROM THREE AREAS. THE FIRST AREA INVOLVES COMPUTER AIDS THAT HELP TO INTERPET TEST DATA AND OPTIMIZE LOCATIONS OF ACTIVE CONTROL SENSORS AND ACTUATORS. THE COMPUTER AIDS ARE BASED ON ADVANCED MULTIPLE INPUT COHERENCE ANALYSIS ALGORITHMS (DESIGNATED MICARDS) WHICH QUANTIFY, CHARACTERIZE, AND PINPOINT THE CAUSES OF NOISE AND VIBRATION. THE RESULTS FROM MICARDS PROCESSING OF TEST DATA LET THE DESIGNER TAILOR A MODIFICATION KIT DESIGN TO TREAT THE DOMINANT SOURCES AND TRANSMISSION PATHS. THE SECOND CATEGORY OF CONTRIBUTION COMES FROM THE CONTINUING ADVANCES IN THE REQUISITE TECHNOLOGIES WITH WHICH TO IMPLEMENT ANVC . LOWER COST AND MORE POWERFULL SIGNAL PROCESSORS NOW EXIST TO PERFORM THE MEASUREMENTS AND THE COMPUTATION OF ACTUATOR COMMANDS TO CANCEL SOURCES OF NOISE AND TO BLOCK TRANSMISSION PATHS. ADVANCES IN ACTUATORS AND SENSORS ARE ALSO IMPORTANT CONTRIBUTIONS THAT ENHANCE FEASIBILITY OF ANVC. FOR EXAMPLE., NEW PROOF-MASS, REACTIONLESS , ELECTROMAGNEIIC ACTUATORS PROVIDE NEW MEANS TO ACTIVELY SURPRESS THE VIBRATIONS OF SHELTER AND VEHICLE PANELS AND STRUCTURAL NUMBERS. THE FINAL AREA THAT WILL BE CONSIDERED IS MANUFACTURING . THE AFFORDABIBTY OF ANVC FOR ARMY APUS IS GREATLY ENHANCED BY THE DEVELOPMENT OF A MARKETING AND MANUFACTURING PLAN WHICH IS FOUNDED ON THE PHILOSOPHY THAT STANDARD ANVC MODULES WILL HAVE APPLICABILITY IN A VERY BROAD TARGET MARKET. THE BENFITS OF HIGH VOLUME ON KEEPING THE ANV